It depends if your coil is up to it.
What coil are you running?
A stock unit or a 60,000 volt HEI coil like mine?
If your running a high output coil, yes, .045 gap is fine.

View coil pictures by clicking on the red link below my name.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

It's stock, as far as I can tell the car is bone stock inside and out.

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1978 4 door Dodge Aspen, Super Six

I have done .037 on stock electronic. Benifit? Possibly. .050?!! Wow that is big!

Too much gap there would have to be problems, over heating the coil, wires not capable of handling the current.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

I run HEI with premium Standard distributor cap, long-tip Echlin rotor, Magnecor plug wires and NGK UR45IX plugs in my Aspen super six. Very good plugs, come pregapped at .059". Recommended.

Olaf

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Aspenized

I regapped my plugs at .42" and it runs great, although I cant tell any real difference in performance. I hope to see some difference in mileage though hopefully. I have a Blue Streak ch-410 cap coming and am now looking for one of the long tipped rotors and will install those next. Cheers, Sam

Someone please correct me if I am wrong. Can you over heat a box with too big of a gap?

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

No, but you can over heat a coil. That is why I started mounting them on the fender to monitor temps away from the engine heat. I went through about 4 different coils until I found the 60,000 volt 3 ohm Pertronix HEI style. It runs luke warm year round with the plugs gapped at .045.

Even the MSD Blaster would get blistering hot mounted on the fender.

My orange box never gets more than luke warm.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Re. hot coil: Also be aware of, that the NGK spark plugs with the super thin iridium center electrode, puts a much smaller strain on the coil than spark plugs with conventional electrodes, even with the big .059" gap. The UR45IX only fits the 75->up 'peanut' cylinder heads, I don't know if similar plugs exist for the earlier heads.

Olaf

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Aspenized

I'm a little confused after reading some posts about wether or not I need to remove the washers from my NGK long tipped plugs. I have a 1975 head wich is what I assume is referred to as a "peanut" style head? Or do you just need to remove the washers on these plugs on the older heads? Right now I have them on. Sam

Yes, that's the peanut plug head...These plugs seal to the chamber by using the tapered edge above the threads on the plug...they do not have/come with washers and there are fewer threads in contact with the spark plug body in the head compared to the drool tube head...

Unlike the drool tube head the area around the plug is not machined or spot faced to support the edge sealing like the drool tube plugs, so if you are installing a set of ZFRN-5's into a 1975-1987 head, you are on borrowed time for keeping the plug sealed properly. If you have the money you can have a machinist spot face the plug holes and see if they will stay sealed with or without the rings and have him open up the area so a 13/16" plug socket would fit right in that area if needed.

There currently is no equivalent to the ZFRN plug for the peanut head inside the automotive industry. If needing more reach your could swap the UR-4/5 plugs for a set of TR-4 plugs for another 3/8" reach inside the chamber but: If your piston clearance it tight the extra threads will clash with the piston top and if not, the thread can become so carboned up you may need to remove the head to clean them so they can be removed. (THe 21st century corvette plugs will also fit giving you a 1" reach into the chamber, but again they will collide with the up coming piston among other things...)

-D.Idiot

"No, I'm the guy that spent time looking through catalogs at this, and bought them other plugs and saw what they looked like when installed in a head...Peanut Plug= easy to get plug every classic chevy uses them, but no chance on getting plugs with other configurations."

Hi SlantedTrucker.
To be certain of which type of head you have, take a look at the photos of the different style cylinder heads in these links;

http://www.slantsix.org/articles/sa-franks-book/pg5.jpg for the old style head,
and
http://www.slantsix.org/articles/sa-franks-book/pg6.jpg for the newer head.

Some more detailed photos of the old style cylinder head, in this link to one of Doc's engine builds: http://www.slantsix.org/forum/viewtopic ... ht=#166560

BTW, I recommend all of you to follow the links to wisdom in Best of Doctor Dodge in the engine FAQ.

Olaf

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Aspenized

Thanks DI and Olaf for setting me straight on the difference between all the different style heads, I'm lucky I didn't screw this engine up by putting the long threaded plugs in my peanut head! They weren't in there but a few hundred miles and I just took them out to regap so I know they will still come out ok. I'm glad I asked before they were indo long the carbon wouldn't let em come back out! This is why its good to ask questions if your unsure. I have some new Autolite platinum plugs for the peanut head I can put back in but is there another plug you guys would recommend? Thanks again guys for saving me from myself on this! Sam

NGK UR-5 for cold plug, and UR-4 for hot plug...I noticed that on the hpak car it really is dialed in with the goldilocks syndrome: UR-4 is too hot, UR-5 is too cold...oddly AC Delco R-45TS is right in the middle at .040-.042 gap and is just right.

Go figure.

-D.Idiot

Autolite is made in China now. NGK goes in everything except my dually.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

And the UR45IX is also right in the middle. They have a perfect very light tan color in my otherwise stock engine, apart from the ignition setup. I have used NGK UR4 for many years with good result, but the best spark plug that I previously used in the SL6, was the old US made Autolites. I still have a set, brand new...
Yup.

Olaf

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Aspenized